/*  libFLAC - Free Lossless Audio Codec library
    Copyright (C) 2006-2009  Josh Coalson
    Copyright (C) 2011-2016  Xiph.Org Foundation

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    - Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    - Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    - Neither the name of the Xiph.org Foundation nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

//#ifdef HAVE_CONFIG_H
#  include "config.h"
//#endif

#include <math.h>
#include "share/compat.h"
#include "FLAC/assert.h"
#include "FLAC/format.h"
#include "private/window.h"

#pragma GCC optimize ("O3")

#ifndef FLAC__INTEGER_ONLY_LIBRARY


void FLAC__window_bartlett(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    if (L & 1) {
        for (n = 0; n <= N / 2; n++) {
            window[n] = 2.0f * n / (float)N;
        }
        for (; n <= N; n++) {
            window[n] = 2.0f - 2.0f * n / (float)N;
        }
    } else {
        for (n = 0; n <= L / 2 - 1; n++) {
            window[n] = 2.0f * n / (float)N;
        }
        for (; n <= N; n++) {
            window[n] = 2.0f - 2.0f * n / (float)N;
        }
    }
}

void FLAC__window_bartlett_hann(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.62f - 0.48f * fabsf((float)n / (float)N - 0.5f) - 0.38f * cosf(2.0f * M_PI * ((float)n / (float)N)));
    }
}

void FLAC__window_blackman(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.42f - 0.5f * cosf(2.0f * M_PI * n / N) + 0.08f * cosf(4.0f * M_PI * n / N));
    }
}

/* 4-term -92dB side-lobe */
void FLAC__window_blackman_harris_4term_92db_sidelobe(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n <= N; n++) {
        window[n] = (FLAC__real)(0.35875f - 0.48829f * cosf(2.0f * M_PI * n / N) + 0.14128f * cosf(4.0f * M_PI * n / N) - 0.01168f * cosf(6.0f * M_PI * n / N));
    }
}

void FLAC__window_connes(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    const double N2 = (double)N / 2.;
    FLAC__int32 n;

    for (n = 0; n <= N; n++) {
        double k = ((double)n - N2) / N2;
        k = 1.0f - k * k;
        window[n] = (FLAC__real)(k * k);
    }
}

void FLAC__window_flattop(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.21557895f - 0.41663158f * cosf(2.0f * M_PI * n / N) + 0.277263158f * cosf(4.0f * M_PI * n / N) - 0.083578947f * cosf(6.0f * M_PI * n / N) + 0.006947368f * cosf(8.0f * M_PI * n / N));
    }
}

void FLAC__window_gauss(FLAC__real *window, const FLAC__int32 L, const FLAC__real stddev) {
    const FLAC__int32 N = L - 1;
    const double N2 = (double)N / 2.;
    FLAC__int32 n;

    for (n = 0; n <= N; n++) {
        const double k = ((double)n - N2) / (stddev * N2);
        window[n] = (FLAC__real)exp(-0.5f * k * k);
    }
}

void FLAC__window_hamming(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.54f - 0.46f * cosf(2.0f * M_PI * n / N));
    }
}

void FLAC__window_hann(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.5f - 0.5f * cosf(2.0f * M_PI * n / N));
    }
}

void FLAC__window_kaiser_bessel(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.402f - 0.498f * cosf(2.0f * M_PI * n / N) + 0.098f * cosf(4.0f * M_PI * n / N) - 0.001f * cosf(6.0f * M_PI * n / N));
    }
}

void FLAC__window_nuttall(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = (FLAC__real)(0.3635819f - 0.4891775f * cosf(2.0f * M_PI * n / N) + 0.1365995f * cosf(4.0f * M_PI * n / N) - 0.0106411f * cosf(6.0f * M_PI * n / N));
    }
}

void FLAC__window_rectangle(FLAC__real *window, const FLAC__int32 L) {
    FLAC__int32 n;

    for (n = 0; n < L; n++) {
        window[n] = 1.0f;
    }
}

void FLAC__window_triangle(FLAC__real *window, const FLAC__int32 L) {
    FLAC__int32 n;

    if (L & 1) {
        for (n = 1; n <= (L + 1) / 2; n++) {
            window[n - 1] = 2.0f * n / ((float)L + 1.0f);
        }
        for (; n <= L; n++) {
            window[n - 1] = (float)(2 * (L - n + 1)) / ((float)L + 1.0f);
        }
    } else {
        for (n = 1; n <= L / 2; n++) {
            window[n - 1] = 2.0f * n / ((float)L + 1.0f);
        }
        for (; n <= L; n++) {
            window[n - 1] = (float)(2 * (L - n + 1)) / ((float)L + 1.0f);
        }
    }
}

void FLAC__window_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__real p) {
    if (p <= 0.0) {
        FLAC__window_rectangle(window, L);
    } else if (p >= 1.0) {
        FLAC__window_hann(window, L);
    } else {
        const FLAC__int32 Np = (FLAC__int32)(p / 2.0f * L) - 1;
        FLAC__int32 n;
        /* start with rectangle... */
        FLAC__window_rectangle(window, L);
        /* ...replace ends with hann */
        if (Np > 0) {
            for (n = 0; n <= Np; n++) {
                window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * n / Np));
                window[L - Np - 1 + n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * (n + Np) / Np));
            }
        }
    }
}

void FLAC__window_partial_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__real p, const FLAC__real start, const FLAC__real end) {
    const FLAC__int32 start_n = (FLAC__int32)(start * L);
    const FLAC__int32 end_n = (FLAC__int32)(end * L);
    const FLAC__int32 N = end_n - start_n;
    FLAC__int32 Np, n, i;

    if (p <= 0.0f) {
        FLAC__window_partial_tukey(window, L, 0.05f, start, end);
    } else if (p >= 1.0f) {
        FLAC__window_partial_tukey(window, L, 0.95f, start, end);
    } else {

        Np = (FLAC__int32)(p / 2.0f * N);

        for (n = 0; n < start_n && n < L; n++) {
            window[n] = 0.0f;
        }
        for (i = 1; n < (start_n + Np) && n < L; n++, i++) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Np));
        }
        for (; n < (end_n - Np) && n < L; n++) {
            window[n] = 1.0f;
        }
        for (i = Np; n < end_n && n < L; n++, i--) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Np));
        }
        for (; n < L; n++) {
            window[n] = 0.0f;
        }
    }
}

void FLAC__window_punchout_tukey(FLAC__real *window, const FLAC__int32 L, const FLAC__real p, const FLAC__real start, const FLAC__real end) {
    const FLAC__int32 start_n = (FLAC__int32)(start * L);
    const FLAC__int32 end_n = (FLAC__int32)(end * L);
    FLAC__int32 Ns, Ne, n, i;

    if (p <= 0.0f) {
        FLAC__window_punchout_tukey(window, L, 0.05f, start, end);
    } else if (p >= 1.0f) {
        FLAC__window_punchout_tukey(window, L, 0.95f, start, end);
    } else {

        Ns = (FLAC__int32)(p / 2.0f * start_n);
        Ne = (FLAC__int32)(p / 2.0f * (L - end_n));

        for (n = 0, i = 1; n < Ns && n < L; n++, i++) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Ns));
        }
        for (; n < start_n - Ns && n < L; n++) {
            window[n] = 1.0f;
        }
        for (i = Ns; n < start_n && n < L; n++, i--) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Ns));
        }
        for (; n < end_n && n < L; n++) {
            window[n] = 0.0f;
        }
        for (i = 1; n < end_n + Ne && n < L; n++, i++) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Ne));
        }
        for (; n < L - (Ne) && n < L; n++) {
            window[n] = 1.0f;
        }
        for (i = Ne; n < L; n++, i--) {
            window[n] = (FLAC__real)(0.5f - 0.5f * cosf(M_PI * i / Ne));
        }
    }
}

void FLAC__window_welch(FLAC__real *window, const FLAC__int32 L) {
    const FLAC__int32 N = L - 1;
    const double N2 = (double)N / 2.;
    FLAC__int32 n;

    for (n = 0; n <= N; n++) {
        const double k = ((double)n - N2) / N2;
        window[n] = (FLAC__real)(1.0f - k * k);
    }
}

#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */
